In a letter to a senior NHS Lothian executive, Hazel Dowling, manager of a Lothian GP practice, expressed concern about the shortage of GPs - but said policy makers had "no idea" about the reality on the ground.
Her comments were leaked to The Herald as the Royal College of GPs Scotland (RCGPS) also warned general practice is at breaking point, with some doctors having to squeeze in 60 patients a day.
Better community care is key to the Scottish Government's plan to look after the growing number of elderly, but there are signs too few junior doctors want careers in general practice, with 35 GP training places unfilled this year.
Mrs Dowling, practice manager for West Calder Medical Practice, sent her email to Professor Alex McMahon, director of strategic planning for NHS Lothian.
She wrote: "There are consistently two or three vacancies being advertised via the NHS Lothian e-mail system, and practices are quite simply unable to recruit replacement doctors.
"In 25 years working in general practice I cannot recall a time when there was so much pressure on general practice, and so few locum doctors around able to help out in times of crisis."
She continued: "Time and time again decisions are taken by people who have no idea of the pressures we are under, or even what we do.
"This was demonstrated at a recent NHS/Scottish Government training event that I attended, when it was clear that the understanding was that general practitioners have a schedule which dictates that they work a 9am-5pm type day which includes large periods blocked out for administrative purposes.
"In reality my GPs are regularly here pre-7.15am and post-8pm as well as coming in to catch up with admin at the weekend."
The latest figures from the RCGPS suggest patient appointments have grown by 10 per cent in the last 10 years - but the proportion of the NHS budget spent on general practice has dropped.
There were an estimated 24.2 million consultations in surgeries with nurses and doctors in 2012-13, up 2.5m compared to 2003-04.
Dr John Gillies, chair of the RCGPS, said: "Demands on general practices across the country are rising continuously. At the same time, resources allocated to deliver the care those practices offer have been steadily shrinking for years. Unless the scales are put back into balance, current GP care provision in Scotland cannot be sustained."
It is thought some doctors are being put off careers in general practice or retire early because it has become so demanding. There is also concern too few junior doctors have the chance to experience general practice before they decide the direction of their career.
Professor McMahon said the board's 10-year plan sought more GP and community-based care.
He said: "In order to provide this we need to increase the primary-care workforce and review and expand premises, ensuring more services are available to patients closer to home. We are currently undertaking a review of GP and practice staff numbers and the suitability and location of premises to identify areas for development. "
A Scottish Government spokeswoman said: "Recruitment into GP training remains high, with an 89 per cent fill rate.
"However the Scottish Government is certainly not complacent, and is working on a range of initiatives to improve matters."